Two-and-a-half years ago, at a meeting in Cambridge, leaders of 42 of America's top libraries and research institutions decided that the time had come to build something together. But what was that thing? After a half hour, Robert Darnton told The Atlantic last year, the group was able to agree on a single sentence: "It's a worthy effort, and we are willing to work together toward it." The "it" in question: a national, digital public library.
If that moment was the Digital Public Library of America's conception, then today is its birth, with the launch of DP.LA, the effort's online home. I asked executive director Dan Cohen about what the DPLA had become in those intervening 20 months, and how he saw its role in American public life going forward. A lightly edited transcript of our conversation follows.

What is the Digital Public Library of America? What do you hope it will become?
The idea behind the Digital Public Library of America is fairly simple actually -- it is the attempt, really a large-scale attempt, to knit together America's archives, libraries, and museums, which have a tremendous amount of content -- all forms of human expression, from images and photographs, to artwork, to published material and unpublished material, like archival and special collections. We want to bring that all together in one place.
One big part of the DPLA will be its brand-new website, DP.LA -- a nice, short URL. It works great on mobile phones too. It's a modern, responsive website.
But also, by bringing them together, I think we're also in a sense making those collections much more usable. When people come to the website, first of all, they'll be able to find a lot of content that exists out in smaller archives and collections much more easily. They won't have to go to hundreds or thousands of websites to find this amazing, unique scanned content from America's heritage and, indeed, from the world's -- because we have people from all over the world here, and archival content from all over the world.
So there will be a real element of discovery -- both directed discovery and also coming across new things through serendipity, things you might not encounter otherwise.
There will also be very innovative ways to search and scan across these collections. For the first time users will be able to actually browse an archive's collections using a map. We're using Open Street Map and people will be able to zoom into particular localities and see what any collection might have about that particular locality -- whether it's a big collection like the Smithsonian or the National Archives or a very small county historical society.
Beyond those really innovative discovery tools, there will also be two other elements to the DPLA that, I think, people may not get right away by going to the site. The second main thing, beyond the portal at DP.LA, is that we will have a platform that others can build upon. All the data will be licensed under CC0 -- that's really a public domain declaration. It means that we're giving away all this data for free for people to use in whatever way they want. And we will have an API -- a very powerful API -- that third-party developers will be able to use to create innovative apps based on the contents of the DPLA. So if you're a developer of a mobile app, maybe one for a local walking tour of a city, you can take the material you already have and mix it up with all the great content from the DPLA for that particular location.
And indeed as part of the process of ingesting this information about all of these items from all across the country, we are in the process of geocoding as much of them as possible, so that they'll work great in those kinds of GPS-based devices and apps. So, that platform is going to be a big part of it and we're hoping to see a lot of partners -- commercial and non-profit -- use that.
Then I think the third big piece is that the organization is really going to act as a very strong advocate for public options for reading and research in the 21st century. We really want to work to expand the realm of publicly available materials. So, obviously, a big part of that is working with non-profit groups like libraries, archives, and museums to get that stuff online and out to the public, but there will also be a component here where I'm going to push, along with my colleagues at the DPLA, to see how we can get other materials into the DPLA and out to the public. It very much has that spirit of the public library. We want to make the maximal amount of content available in a maximally open way.
I think that there will be initiatives that you see in the coming years to work on things like e-books, which are kind of a mess right now; it's really hard to even lend an e-book to your partner, compared with a physical book. We'll be looking at ways, for instance alternative licensing, to make content available as much as possible.